title: Butylated hydroxytoluene chemoprevention of aflatoxicosis - effects on aflatoxin B(1) bioavailability, hepatic DNA adduct formation, and biliary excretion.
abstract: The extreme sensitivity of turkeys to aflatoxin B(1) (AFB(1)) is associated with efficient hepatic cytochrome P-450 (P450)-mediated bioactivation, and deficient glutathione S-transferase (GST) mediated detoxification. Butylated hydroxytoluene (BHT) protects against AFB(1) toxicity in turkeys through mechanisms that include competitive inhibition of P450-mediated AFB(1) bioactivation. To test whether dietary BHT alters hepatic AFB(1)-DNA adduct formation, excretion, and bioavailability of AFB(1)in vivo, turkeys were given diets with BHT (4000ppm) for 10 days, given a single oral dose of [(3)H]-AFB(1) (0.05microg/g; 0.02microCi/g), then sampled at intervals up to 24h. Radiolabel in serum, red blood cells, liver, and breast meat was frequently lower in BHT-treated compared to control. Hepatic AFB(1)-DNA adducts in BHT-treated turkeys were significantly lower at 12 and 24h. BHT-fed birds had significant higher bile efflux, though biliary radiolabel excretion was not different from control. The amount of aflatoxin M(1) (AFM(1)) excreted in the bile was lower than in control, but BHT had no effect on the biliary excretion of AFB(1), aflatoxin Q(1) or glucuronide and sulfate conjugates. Thus, the chemopreventive properties of BHT may also occur through a reduction in AFB(1) bioavailability in addition to inhibition of bioactivation.
authors.affiliation: Department of Veterinary Sciences, Utah State University, Logan, UT 84322-4620, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Guarisco
authors.forename: J O
authors.initials: JO
authors.lastname: Hall
authors.forename: R A
authors.initials: RA
authors.lastname: Coulombe
mesh_terms: D016604:Aflatoxin B1 / Q000493:pharmacokinetics*; D000348:Aflatoxins / Q000037:antagonists & inhibitors / Q000633:toxicity*; D000818:Animals; D001646:Bile / Q000378:metabolism*; D001682:Biological Availability; D001835:Body Weight / Q000187:drug effects; D002084:Butylated Hydroxytoluene / Q000494:pharmacology / Q000627:therapeutic use*; D018736:DNA Adducts / Q000187:drug effects*; D005520:Food Preservatives / Q000494:pharmacology / Q000627:therapeutic use*; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009929:Organ Size / Q000187:drug effects; D014018:Tissue Distribution; D014422:Turkeys / Q000378:metabolism*
chemical_list: D000348:Aflatoxins; D018736:DNA Adducts; D005520:Food Preservatives; D002084:Butylated Hydroxytoluene; D016604:Aflatoxin B1